Treatment of textile fabrics



Dec. 23, 1941. MANN ETAL 2,267,117

TREATMENT OF TEXTILE FABRICS Filed Feb. 1, 1939 .MANN WAR MTLWA Patented Dec. 23, 1941 don, near Derby, England, aesignors to Celnnese Oorporatloui America, a corporation of Dela- Applicatlon February 1, 1939. Serial No. 254,046 In Great Britain April 9, 1938 1 Claim. 01. sat-11s) .This invention relates to improvements in the shrinking of textile fabrics.

According to the invention, fabric is fed at a predetermined rate and substantially without tension to one side of a spreader that engages the full width of the fabric and depresses the fabric below the surface of shrinking liquor in a bath,

and after passing the spreader the fabric moves through the shrinking liquor, being drawn along by a roller driven at a predetermined peripheral speed lower than the rate of delivery of the fabric so that the fabric is permitted to shrink. The

fabric then passes to a washing bath, the roller fabric into the bath taking place smoothly in a length that is maintained free from creases by the lip and the edge of the spreader. The lip and spreader offer Yvery little resistance to the movement of the fabric and thus enable the fabric to be drawn along the bath under such low tension that shrinkage readily takes place. The fabric remains immersed in the bath until it approaches the delivery roller, when it rises sharply out of the bath and passes over the roller.

until it has passed clear of the bath it does not come into contact with any mechanism likely ,to crease the fabric or locally engage its surface, either of which conditions might tend to cause marks to show in the finished fabric. The smooth passage of the fabric into and out of the bath provided bythe arrangement described greatly assists in the uniform treatment of the fabric.

leaves, a weir or other flow arrangement being provided at the opposite end. On being withdrawn from the washing bath the fabric is batched in any suitable way.

The invention may be used in connection with the shrinking of different types of fabric, and is particularly useful for the treatment of cellulose acetate or other cellulose derivative fabrics to impart improved appearance and handle. Thus, fabrics made of or containing cellulose acetate yarns, e. g. taifetas, plain or striped shirtings, and fabrics containing boucl or other fancy yarns, may be subjected to shrinking in acetone, dioxane, ethyl alcohol, isopropyl alcohol, ammonium thiocyanate, or nitric acid, the shrinking agents being used in suitable concentration. Appropriate wash liquors are employed, aqueous washing being suitable for all the agents above mentioned.

. one form of apparatus; and

Fig. 2 is a similar view of a simplified apparatus.

The fabric I is drawn from a-supply roll 2 at a predetermined rate by feed rollers 3 fromwhich itis discharged downwardly at the lefthand end of a shrinking bath 4 along which it moves to the right, and from there passes, into a washing bath 5 from which it emerges at the From the time the fabric leaves the spreader left-hand end to be batched on a roll 6.

The feed rollers 3 cause the fabric to fall freely on to a flat tray I mounted just clear of the shrinking liquor in the bath 4. ,From the 40 loose fold 8 of fabric on the tray 1 the fabric is It is preferable to avoid any local contacting of the fabric with parts of the apparatus during the washing step. An endless blanket may be used to support the fabric during its passage through the washing bath and ensure even treatment during this step, and during such passage the fabric is preferably exposed to a counter-current of wash liquor which may conveniently be maintained by the constant introduction of fresh as indicated at H.

drawn over an upstanding lip 9 formed at the right-hand edge of the tray, and passes downwardly under the edge of a spreader board l0 dipping below the surface of the shrinking liquor. The slight tension thus imparted to the fabric at the-point where it enters the liquor maintains the fabric in open width, without creases. The fabric is uniformly exposed to the shrinking liquor while it remains submerged in the liquor As the fabric reaches the point l2 the pull of a delivery roller l3 withdraws the fabric fairly sharply from the liquor.

The roller i3 is driven at a peripheral speed less by a predetermined amountthan the peliquor at the end of the bath at which the fabric ripheral speed of the rollers 3 to allbw the shrinkage to take place. Advantageously, a variable speed gear is employed to control the relative speeds of the rollers 3 and the roll I! in accordance with the amount of shrinkage desired. r

From the roll l3 the fabric passes downwardly in the vertical run I4 and is there washed on both sides by spray pipes l5 supplied with fresh wash liquor. At the point 16 the fabric enters the wash liquor in the bath 5 and is deposited on an endless blanket I! which enables a long run l8 to be uniformly exposed to the wash liquor.

To allow for any further shrinkage occurring during washing off in the bath 5, a variable speed gear may be arranged to control the relative speeds of the roll I 3 and the rollers l9 carrying the blanket H. The washed fabric leaves the blanket I! at the point 20 and is taken upon the batch roll 6 at a constant speed provided by the driving roll 2|. Fresh wash liquor is introduced into the bath by the spray pipe 22, a lip 23 allowing for the overflow of spent liquor into the waste pipe 24. The fabric collected on the batch roll 6 is slack dried in any suitable apparatus.

In the apparatus shown in Fig. 2 the blanket I! and its rollers I! of Fig. 1 are omitted, this simplified form of apparatus being suitable in cases where after removal of the major part of the shrinking liquor the fabric is strong enough to proceed through the wash liquor in the bath 5 without support.

' 1y without tension towards the bath, a tray adapted to receive the substantially tensionless fabric is drawn as it passes to the spreader, and means to cause the fabric to slide past the spreader and to draw the fabric through the bath at a definite rate lower than the rate of feed of the fabric, the said means serving to withdraw the fabric from the bath.

RALPH JAMES MANN. WILFRED HARMER. 

